1. Field of the Invention
The present invention relates to a supporting structure for a fuel tank mounted on a vehicle and an automobile assembling method for mounting the fuel tank.
2. Description of the Related Art
Generally, a fuel tank in a vehicle is located under a rear seat, and such a layout is adopted in various types of vehicles. For example, Japanese Patent Laid-open No. Hei 6-286484 discloses a supporting structure for a fuel tank such that the fuel tank is mounted to a subframe to subassemble a rear suspension module, which is in turn mounted to a main frame. The supporting structure disclosed in this publication is intended to increase a substantial capacity of the fuel tank by setting the mounting position of a breather pipe with respect to the fuel tank to a high position. The fuel tank is supported by the subframe under the rear seat.
Further, Japanese Patent Laid-open No. 2000-255448 discloses a rear subframe structure for a vehicle such that saving of the installation space for a rear subframe and improvement in rigidity of supporting of a differential unit are intended. In this rear subframe structure, a fuel tank is reduced in thickness at its central portion so as to avoid the interference with a propeller shaft, so that the fuel tank is composed of a right tank portion and a left tank portion and located on the front side of the rear subframe under the rear seat.
There is a desire such that the flexibility of arrangement of suspension arms is to be improved for the purposes of improvement in rear suspension performance. However, the above-mentioned arrangement in the related art has a problem such that the tank capacity of the fuel tank cannot be ensured and the fuel tank is located at a position where the volumetric efficiency is low, causing an increase in weight of the fuel tank and an adverse effect on the cabin comfort of the vehicle. If the tank capacity of the fuel tank is intended to be ensured with a high volumetric efficiency, it is difficult to ensure the rigidity of the subframe for supporting the suspension arms or the rigidity of suspension arm mounting points on a vehicle body.